1. Field of the Invention
The present invention relates to a speed hump device, and more particularly to a speed hump device for discouraging motor vehicles form exceeding a demanded threshold speed.
2. Description of the Prior Art
One such known traditional speed hump 100, as shown in FIG. 1, is a so-called “sleeping policeman” including one or more raised portions as humps extending across, usually fully across, the “controlled” road or traffic surface. By the sufficient height of the raised portions, the traditional speed hump 100 causes noticeable impact or jolt effect to cars or other motor vehicles. In general, although different traditional speed humps could be designed to any kind of figure and made of different materials, they have all motor vehicles run thereon suffered a uncomfortable impact effect weather the speed of the motor vehicles are fast or slow, and that is real a torment to a diver who obey the traffic rule and drive slowly, specially, slower than a demanded threshold speed, further, that also causes harm to the motor vehicles.
Additionally, drivers meeting the traditional speed hump 100 for the first time usually assume that it will provide a severe impact, so that those wishing to avoid such an impact effect need to slow down to a very low traverse speed, no matter what the actual height of the traditional speed hump 100 and the very low traverse speed may be much lower than necessary, namely, slowing down the car more than which is required. Therefore, the traditional speed hump 100 is not suitable for most traffic roads. Another traditional traffic hump 200 is shown as FIG. 2. The traditional traffic hump 200 will cause an impedimental effect to the motor vehicles whose going direction against the traffic flow direction to prevent them from passing through the traditional hump 200. However, the traditional traffic hump 200 could not be used to be a speed hump, as the traditional speed hump 100 shown in FIG. 1, since the sharp figure of the traditional traffic hump 200 will cause serious harm to a running car.
Due to the disadvantages of the traditional speed humps mentioned above, it needs to provide a speed hump device which can automatically determine weather let a motor vehicle get a smooth road surface or not according to its speed. For example, when the speed of a running car is over a demanded threshold speed, the hump member of the provided speed hump device would be in the position above the road surface and that causes an uncomfortable impact or jolt effect to the running car; and when the speed is below the demanded threshold speed, the hump member will be depressed into alignment with the road surface by the wheels of the running car and the uncomfortable impact or jolt effect will disappear, then the running car traverses the road smoothly. Besides, the provided speed hump device has an impedimental effect to the motor vehicles whose going direction against the traffic flow direction. Furthermore, it does not need to consume any additional energy to drive the provided speed hump device.